Agricultural combines work in environments that are quite dirty. The primary source of the dirt is the combine vehicle itself. As it harvests crop, it crushes and separates dried plant stalks and leaves from the grain or seed produced by the crop plant. The method of separating the grain from material other than grain (MOG) includes blasting the mixed MOG and grain with a high volume of air which billow around the vehicle.
The large volume of dirty air requires a large air inlet with a large cleaning element for engine cooling air. In one arrangement common to many agricultural combines, a large circular screen filter is disposed across an air inlet to the engine radiator and cooling air fan. This screen rotates to continuously clean the screen during operation. The circular screen is typically disposed in a panel that can be opened to provide access to the radiators. The circular screen may also be enclosed with a large scoop that only permits air to flow downward from above the filter in a direction generally parallel to the surface of the filter and into the filter. Relatively clean air from above the vehicle is thereby directed downward across the face of the filter and is pulled into the filter.
U.S. Pat. No. 4,906,262 shows a self-cleaning rotary screen for the cooling inlet of an agricultural combine. The rotary screen is generally planar and circular and is disposed slightly inside the side walls of the combine.
U.S. Pat. No. 4,233,040 is directed to a self-cleaning rotary filter for the cooling air inlet of an engine enclosure that is fixed to a hinged and generally rectangular panel on the side of an agricultural combine. The panel that supports the rotary filter can be pivotally opened, about a vertical axis defined by two hinges to provide access to the cooling package of the engine.
US200610283157 is directed to a self-cleaning rotary filter disposed on a rectangular panel that is fixed to the side of an agricultural combine. A shroud or shield is provided around the rectangular panel (FIG. 1) to limit airflow into the rotary filter. The shroud provides an opening above the panel on which the rotary filter is mounted such that are entering the filter must flow down from directly above the filter.
In each of these arrangements, all of the cooling air is sucked through the rotary filter, which is smaller than the size of the rectangular panel on which the rotary filter is mounted.
The problem the present invention is intended to solve is that of the limited airflow to a cooling package that is provided by a rotary screen installed in a rectangular panel. It is an object of this invention to solve that problem.